deprecated in favor of MLM extension

The *Machine Learning Model (MLM)* extension (https://github.com/crim-ca/mlm-extension) combines the fields that were previously defined in the *Deep Learning Model (DLM)* extension as well as most (all?) fields proposed by ML-Model. Some fields are renamed to avoid redundant details between the 2 references, while others are adjusted to allow more flexibility (e.g.: not just docker-compose runtime, but virtually anything). More best-practices and examples are provided to demonstrate the use of MLM along other STAC extensions to take advantage of the full STAC ecosystem.

Schema for MLM: https://crim-ca.github.io/mlm-extension/v1.0.0/schema.json

README.md

@@ -1,10 +1,16 @@
 # ML Model Extension Specification
 
+> :warning: <br>
+> This repository is deprecated in favor of
+> [https://github.com/crim-ca/mlm-extension](https://github.com/crim-ca/mlm-extension). <br>
+> The corresponding schemas are made available on
+> [https://crim-ca.github.io/mlm-extension/](https://crim-ca.github.io/mlm-extension/).
+
 - **Title:** ML Model
 - **Identifier:** <https://stac-extensions.github.io/ml-model/v1.0.0/schema.json>
 - **Field Name Prefix:** ml-model
 - **Scope:** Item, Collection
-- **Extension [Maturity Classification](https://github.com/radiantearth/stac-spec/tree/master/extensions/README.md#extension-maturity):** Proposal
+- **Extension [Maturity Classification](https://github.com/radiantearth/stac-spec/tree/master/extensions/README.md#extension-maturity):** Deprecated
 - **Owner**: @duckontheweb
 
 This document explains the ML Model Extension to the [SpatioTemporal Asset